[PATCH v4 6/8] qemu: Enable SCHED_CORE for helper processes

For QEMU_SCHED_CORE_FULL case, all helper processes should be placed into the same scheduling group as the QEMU process they serve. It may happen though, that a helper process is started before QEMU (cold start of a domain). But we have the dummy process running from which the QEMU process will inherit the scheduling group, so we can use the dummy process PID as an argument to virCommandSetRunAmong(). Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; Reviewed-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/qemu/qemu_process.c | 9 +++++++++ src/qemu/qemu_security.c | 11 +++++++++++ src/qemu/qemu_virtiofs.c | 11 +++++++++++ 3 files changed, 31 insertions(+) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 808558227e..22845423ce 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -2848,6 +2848,15 @@ qemuProcessStartManagedPRDaemon(virDomainObj *vm) * qemu (so that it shares the same view of the system). */ virCommandSetPreExecHook(cmd, qemuProcessStartPRDaemonHook, vm); + if (cfg->schedCore == QEMU_SCHED_CORE_FULL) { + pid_t cookie_pid = vm->pid; + + if (cookie_pid <= 0) + cookie_pid = priv->schedCoreChildPID; + + virCommandSetRunAmong(cmd, cookie_pid); + } + if (virCommandRun(cmd, NULL) < 0) goto cleanup; diff --git a/src/qemu/qemu_security.c b/src/qemu/qemu_security.c index 3be1766764..5b7d5f30c2 100644 --- a/src/qemu/qemu_security.c +++ b/src/qemu/qemu_security.c @@ -683,6 +683,9 @@ qemuSecurityCommandRun(virQEMUDriver *driver, int *exitstatus, int *cmdret) { + g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver); + qemuDomainObjPrivate *priv = vm->privateData; + if (virSecurityManagerSetChildProcessLabel(driver->securityManager, vm->def, cmd) < 0) return -1; @@ -691,6 +694,14 @@ qemuSecurityCommandRun(virQEMUDriver *driver, virCommandSetUID(cmd, uid); if (gid != (gid_t) -1) virCommandSetGID(cmd, gid); + if (cfg->schedCore == QEMU_SCHED_CORE_FULL) { + pid_t pid = vm->pid; + + if (pid <= 0) + pid = priv->schedCoreChildPID; + + virCommandSetRunAmong(cmd, pid); + } if (virSecurityManagerPreFork(driver->securityManager) < 0) return -1; diff --git a/src/qemu/qemu_virtiofs.c b/src/qemu/qemu_virtiofs.c index a04aa08e39..cd947bebfd 100644 --- a/src/qemu/qemu_virtiofs.c +++ b/src/qemu/qemu_virtiofs.c @@ -178,6 +178,7 @@ qemuVirtioFSStart(virQEMUDriver *driver, virDomainFSDef *fs) { g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver); + qemuDomainObjPrivate *priv = vm->privateData; g_autoptr(virCommand) cmd = NULL; g_autofree char *socket_path = NULL; g_autofree char *pidfile = NULL; @@ -251,6 +252,16 @@ qemuVirtioFSStart(virQEMUDriver *driver, virCommandNonblockingFDs(cmd); virCommandDaemonize(cmd); + if (cfg->schedCore == QEMU_SCHED_CORE_FULL) { + pid_t cookie_pid = vm->pid; + + if (cookie_pid <= 0) + cookie_pid = priv->schedCoreChildPID; + + virCommandSetRunAmong(cmd, cookie_pid); + } + + if (qemuExtDeviceLogCommand(driver, vm, cmd, "virtiofsd") < 0) goto error; -- 2.35.1